1. Field of the Invention
This invention relates generally to containers received by wall-mounted dispensing devices and used to contain highly viscous material, such as hand cleaner, for dispensing from the dispensing devices. More particularly, the invention relates to a container assembly adapted to be received selectively by either of two such dispensing devices having receiving ports of different sizes.
2. Description of Related Art
Known in the prior art are several arrangements for dispensing viscous fluids such as hand cleaner. One component of each such arrangement is a dispensing device, generally a plastic or metal mechanism intended to be mounted on a wall or similar surface. The other component is a container filled with the material to be dispensed; the container is normally cylindrical in shape and has a removable top cap or member covering an opening which fits on the dispensing device.
A first type of dispensing device employs a spring-loaded reciprocal arm moved by hand pressure to open and close a valve to permit metered amounts of the material to pass out of a nozzle. To affix the cylindrical container to this first type of dispensing device the top cap is removed and the container is inverted into a suitable receiving port on the dispensing device. Receiving ports on such dispensing devices may be any of several different diameters, two popular ones being about 51/4 and about 3 inches respectively.
In order for the material to flow suitably when the container is installed on the first type of dispensing device, it is necessary to provide within the container and resting on the surface of the material a follow or pressure plate having its periphery closely spaced from the container sides; it is also necessary to provide means allowing air into the space above the follow plate. In prior art containers having a diameter matching the receiving port on the dispensing device with which they are used, common practice has been to insert the follow plate in the bottom of the container prior to filling. Then, when the top cap is removed and the container is inverted on the dispensing device, an opening is provided in the bottom of the container to allow air to enter.
Where the receiving port in the first type of dispensing device is of smaller diameter than the container, a suitably sized opening is formed in the container bottom and a removable cap inserted therein. The container is then filled from the open top and a full-diameter top cap is affixed. In use, the bottom cap is removed and the container is positioned on the dispensing device port. The top cap is then removed and a separate follow plate, generally supplied by the manufacturer of the dispensing device, is positioned on the surface of the material being dispensed; often the top cap is repositioned loosely over the open end of the container to keep foreign material out while allowing air to enter the container.
With the first type of dispensing device, a combination of atmospheric pressure acting on the follow plate and the pumping action of the dispensing device itself will provide a measured amount of material to the user.
A second type of dispensing device includes a threaded center post and a ratchet-gear arrangement. A pressure plate is carried on the threaded post which is actuated by the ratchet gearing from a handle. Moving the handle turns the threaded post, which draws the pressure plate down onto the material and forces the material out of a dispensing valve. A typical container used heretofore with the second type of dispensing device is cylindrical and has a knock-out plug centrally disposed in the bottom wall so that the container, once its top cap has been removed, can be inserted over the threaded shaft, following which the pressure plate is mounted on the threaded post and brought into contact with the material, so that actuation of the handle and working of the ratchet gearing draws the pressure plate down and forces the material out of the dispensing nozzle or valve.
Potter U.S. Pat. No. 4,437,589 discloses a container in which the bottom wall has a reduced thickness web at its circumference adjacent the sidewall juncture, whereby after the container is inverted and mounted on the dispensing device, the entire bottom wall can be separated from the container and act as the inside follow plate; in such configuration the top cap, which has been removed to mount the container on the dispensing device, can then be loosely positioned over the bottom (actually the top when the container is inverted) to prevent dirt or other foreign material from falling into the container. Potter's bottom wall also has a reduced diameter centrally located knock-out section defined by a circumferential reduced thickness web, enabling the container to be used with the second type of dispensing device described above.
Although the container of Potter U.S. Pat. No. 4,437,589 is usable with both the first and second above described types of dispensing devices, the configuration of its bottom wall and top cap can be expected to make it difficult and expensive to fabricate.
As previously mentioned, two popular dispensing devices of the first type have have receiving port diameters of about 51/4 inches and about 3 inches respectively. Obvious advantages accrue with an inexpensive container assembly usable with receiving ports of both sizes as well as with dispensing devices of the second type described above.